Apparatus for magnetic separation of iron ore.



PATENTED FEB. 6, 1906.

e. GRUNDAL. APPARATUS FOR MAGNETIC SEPARATION OF IRON ORE.

APPLICATION FILED NOV. 12,1903.

IN VE/VT'O R UNITED sTA'rEs PATENT oFrIoE.

, GUSTAF GRONDAL, OF JUas'HoLM, SWEDEN. APPARATUS FOR MAGNETIC SEPARATION OF IRON ORE- Specification of Letters Patent.

Patented Feb.6,1906.

To all whom it may concern:

Be it known that I, GUSTAF GRoNDAL, a subject of the Kin of Sweden and Norway, and a resident of lDjursholm, Sweden, have invented certain new and useful Improvements in Apparatus for Magnetic Se aration of Iron Ore, (for which I have applied for a patent in Norway, dated April 7, 1903, N 0. 16,254,) of which the following is a specification.

This invention relates to improved apparatus for effecting, by means of amagnetic se aration of pulverized iron ore, a practica lycom lete separation of the most magnetic part1clesthe particles of pure iron orefrom the less magnetic particles and the gangue and at the same time toseparate the latter two from each other. material pulverized to the necessary small size is suspended in water (which may be termed ore-pulp) and led horizontally, or nearly so, through a magnetic field in the proximity of but not in contact with the polepiece of a stationary magnet. By modifying, on the one hand, the force of the magnet and, on the other hand, adjusting the distance between the pole-piece and the surface of the current with the suspended. material and varying the depth and rapidity of said current t e magneticparticles are attracted and separated from the non-magnetic particles at some distance on the side of the pole-piece, and the most magnetic particles'those of pure magnetic iron ore, for instance-in passmg the poleiece are lifted up out of the water toward t e magnet, while the less magnetic particles are not drawn through and out of the water, but remain in a layer at and under the surface of the water, the said layer being richer than the layer underneath. The particles drawn out of the water are gathered separately, and the richer layer of the current containing the less magnetic particles is led off separately to be further enriched, if desired. In order to gather and lead away the particles drawn toward the magnet, each of the pole-pieces of the magnet is surrounded by a hollow drum made of a magnetically-indifferent material, such as zinc or brass, the said drum being kept rotating in the same direction as the current containing the suspended material. The pole-piece is formed with an edge lying behind and near the part of the drum ast which the current is led, the mantle of t e drum being provided with lamellae of iron inserted into it, which carry For this purpose thethe particles along withfthem a bit and then let them loose. Water cts directed against the drum on suitable pliaces 'may, however, be used for removing t em wholly.

In the accompanying drawings there is shown diagrammatically and as an example only a form of apparatusfor carrying out the separation.

Figure 1 is an elevation, partly in section, along the line 1 1 of Fig. 2. Fig 2 is a vertical section along the line 2 2 of ig. 1.

a is an electromagnet. b b are its polepieces, which are formed with a downwardlydirected elongated ed e c.

d is a shaft passing through the magnet and carrying the drums 0 around the ipole-pieces, respectively, and a belt-pulley}: or rotating thedrums. In the drawings t e drum, with the accessory parts, is omitted at one of the pole-pieces.

g is a vessel divided into two compartments 'i and k by an inclined partition h.

l is a supply-pipe for the suspended material entering'into the compartment i, and m is a discharge-pipe provided with a cock from the compartment k.

n is an overf ow-discharge, located a little lower than the top of the partition h.

0 indicates an adjustable late for varying the hei ht of the overfiowischarge. p is. a channe leading therefrom.

q is a channel located above the overflowdischarge.

1' is a water-pipe provided with perforations toward the drum e for washing away the ore particles. t

The a aratus operates as follows: The vessel g is fi l dd with water and the drum e is in rotation. The sus ended material is t en let on through the pipe I, and it rises in the chamber& and over the top of the partition h. From this edge the current containing the suspended material flows toward the overflow-discharge n, and on the way the separation is effected by means of the powerful magnet in such a manner that the magnetic mate rial is drawn upward toward the surface of the current already from the beginning and the non-magnetic material is left to sink. When right under the ed e c of the magnet, the most magnetic particiies are lifted out of the water toward the drum e and they fasten on the latter, while the less magnetic particles flow away over the overflow-discharge "n, 1 10 through the channel and are gathered for further treatment. he non-metallic matem. The

rial, or the gan e, which falls down the compartment 7c is drawn off through the'pipe articles adhering to the rotating drum e fall off and are washed from the drum and fall down into the channel g, being gath ered for further treatment.

The a paratus may be arranged either so that eac tpole-piece treats a separate current of suspen ed material or so t at one of the ole-p1eces treats a portion already separated I y the other pole-piece, the said portion bewith a surface-level in proximity to but not in contact with said moving surface under the magnet-pole, an inlet for the ore whereby it may float suspended in the said liquid, and an outlet for the non magnetic material from the lower part of the compartment, and a channel to carry off the magnetic material which has been drawn out ofthe water.

2. Apparatus .for magnetically separating ores, consisting of a magnet, a moving surface under the magnet-pole, a compartment having an overflow to maintain a body of liquid with a surface-level in proicimity to but not in contact with said moving surface under the magnet-pole and at the same time to carry ofi" the less magnetic particles drawn to the surface of but not out of the water, an inletfor the ore whereby it may float suspended in the said li uid, an outlet for the non-magnetic materia from the lower part of the compartmentand a channel to carry 01f the magnetic material drawn out 'of the water.

'3. Apparatus for magnetically separating ores, consisting of a magnet, a moving surface under the magnetole, two compartments, the first adapte to receive the ore suspended in water and to overflow the same intothe second com artment, the two adapted to maintain the ody of liquid with a surface-level in proximity to, but out of contact aiawo with, said moving surface under the magnetpole, an outlet for the non-magnetic material from the lower part of "the second compartment, and a channel to carry off the magnetic material which has been drawn out of the water.

4. Apparatus for magnetically separating ores, consisting of a magnet, a revolving lamellated drum having the magnet-pole within it, a compartment havin' an overflow to maintain a body of liquid wit a surface-level in proximity to, but not in contact with, the drum-surface under the magnet-pole, aninlet for the ore whereby it may float suspended in the said liquid and an outlet for the nonmagnetic material from the lower part of the compartment and a channel to carry oi? the ma netic material which has been drawn out of t e water.

5. An apparatus for magnetically separating iron ores, comprisinga stationary electromagnet, having a-pole-piece formed with an elongated edge, a rotating hollow drum of a magnetically indifferent material provided with iron lamellse in its mantle surrounding the pole-piece, and meansfor passing the'current containing the sus ended material to be separated past, beneat and out of contact with the drum in such a manner that the direction of motion is at right angles against the edge of the pole-piece of the magnet, and the same as the direction of motion of the drum whose mantle moves between the edge of the pole-piece and the current of water, said means consisting of a vessel located under the drum, a artition dividing it into two compartments ying side by side, the one compartment being fprovided at the bottom 0 with a supply-pipe or the suspended material, and the other compartment being provided at the bottom with a discharge-conduit for the non-magnetic part of the material, and at the'top with an overflow-discharge for the less magnetic part of the material. 1 g

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. i

GUSTAF GRONDAL. Witnesses:

G. Fmnnne, MANFRED Slins'rni'm. 

